Digging teeth for excavating, dippers, etc.



June 23, 1959 L. w. VAN BUSKIRK 2,

-DIGGING TEETH FOR EXCAVATING, DIPPERS, ETC

Filed Sept. 10, 1954 2 Sheets-Sheet 1 1 FIG. 2 4 5? 1V i l 7 k INVENTORL. w.- v n Bus/ark fiizj h ATTORNEY United States Patent {Ofice2,891,333 Patented June 23, 1959 DIGGING TEETH FOR EXCAVATING, DIPPERS,ETC.

7 Lesher W. Van Buskirk, Easton, Pa.

Application September 10, 1954, Serial No. 455,199

8 Claims. ((137-142) My invention relates to improvements in diggingteeth of the replaceable digging point type such as are carried by thedigging lip of power shovel dippers, drag buckets etc. Digging teeth ascharacterized comprise a base section which is secured to the digginglip of the dipper or bucket, and its forward end provides a seat towhich is detachably secured the digging point, or tip, which latterrequiresmore or less frequent replacement, depending upon the characterof material being dug.

' In excavating operations involving rock or coal the digging points ofthese teeth are subjected to tremendous stresses along lines originatingfrom points forwardly of their base sections and from both vertical andlateral directions with respect to the longitudinal axis of the tooth.This means that if the interfitted or seat-providing portions of thetooth base and tip do not provide for adequate stress transfer from thetip to the base from all directions forwardly of the latter there willbe overloading of base-carried portions of the tip and the ultimatebreaking loose of the latter. A broken 01f digging tooth tipmay become adangerous piece of metal because if it subsequently gets into expensiverock or coal crushing machinery it can cause great damage thereto,necessitating a shut-down of operations for costly repairs.

Therefore manufacturers of excavating equipment and others have devotedmuch time and effort to achieve. satisfactory tooth base-provideddigging tip support against the stresses mentioned, but without anyconsiderable degree of success for various reasons. In some instances,the opposed stress transferring surfaces of the tip and base have beenimproperly located or are of insuflicient area, and in other cases theformation of such'surfaces has made it difiicult and expensive if notactually impossible to grind or machine them sufliciently to bring aboutadequate stress-transferring engagement.

Then too, those of the prior art teeth which may be somewhat better thanothers as regards stress transfer from tip to base are difiicult toassemble and separate especially in large sizes due to an over tight orjam fit of the parts in certain areas even though proper stress transferis lacking in other areas.

It is therefore the primary object of my present invention. to overcomethe objections aforenoted and to provide a digging tooth of the classindicated, which is of simple and durable construction providingadequate tipto-base stress transfer, is relatively inexpensive tomanufacture in that it requires but a minimum of easily accomplishedmachining of opposed stress-sustaining portions, and wherein the diggingtip can be readily applied to or removed from the tooth 'base even as tolarge sized teeth.

,A--further and more specific object of my present development is toprovide a tooth base and its separable digging tip which have certaincooperating stress-transmitting portions, the outer ends of which arebrought into engagement prior to the interengagemen-t of otherstress-absorbing portions of the tip and base as the latter areassembled, and which ends are relieved in planes normal to one anotherin a manner to admit of an initial play when assembling and which playwill facilitate both assembly and disassembly of the parts; and whereinthe relieved terminal part of one of said tip and base portiotnssubsequently functions as a cam in conjunction with another part of thecompanion portion to tend to promote stress-sustaining engagement ofother cooperating portions of said tip and base when the latter arefully assembled Additionally, the invention contemplates the provisionof a novel excavating tooth which is characterized by a base-providedseating nose for a removable V-form digging tip having verticallydivergent rearwardly extend ing wings, and wherein opposed parallelrearwardly extending lugs which are wedge shaped in cross-section arecarried by said wings and received in correspondingly shapednose-provided seats, there being a removable and novelly positionedload-sustaining retainer element for maintaining the tip and baseassembled.

Also, having reference to the base nose-provided seats for thewedge-form tip lugs, mentioned in the preceding paragraph, it is an aimof the invention to provide novel means whereby the slanted side Wallsof said seats can be easily and quickly machined to make adequatestressreceiving engagement with the related sides of the wedgeform lugsof the digging tip.

Other objects and advantages of the invention will be developedhereinafter, or will be obvious to those versed in the art, referencebeing bad to the accompanying drawings which illustrate a now preferredexample of my inventive concept. It is to be understood, however, thatthe disclosures herein are to be taken as illustrative rather thanlimitative, as the invention is susceptible of other mechanicalexpressions within the spirit and scope of the subject matter claimedhereinafter.

In the drawings, wherein the same reference characters have been used todesignate the same parts wherever they appear throughout the severalviews- .Figure 1 is a side elevational view partly broken and partly inlongitudinal section of a tooth embodying my invention;

Figure 2 is a fragmentary top plan view thereof;

Figure 3 is a rear perspective view of the digging tip removed andshowing the rearwardly extending wedgeforrn lugs and intermediate boss;

Figure 4 is a fragmentary perspective showing the tipseating forwardportion of the base section of the tooth;

Figure 5 is a view partly broken and showing the tip and adjacent baseportion in central longitudinal section along line 5-5 of Fig. 2;

Figure 6 is a fragmentary perspective illustrating the commencement ofassembly of the digging tip and base' section, the dotted linesindicating the permissable initial play between the parts whichfacilitates the assembly operation; and

Figure 7 is a cross-sectional view of the assembled tooth taken on theline 7-7 of Fig. 2.

Referring to the drawings by reference characters,

. numeral 10 indicates the base section of the tooth, the

' rounded end of nose 11 make contiguous engagementwith' the roundedinner end of the tip-provided seating recess 14 that is bounded top andbottom by the vertically diverging rearwardly extending wings 13 of tip12. As indicated in Figure 2, these tip-provided wings 13 arecoextensive in width with the tip 12 and the base 10, and Figure 1 showshow the opposed inner surfaces of the respective wings 13 inclineoutwardly as at 13a, adjacent to the rear ends thereof. Thus wing endsurfaces 13a make contiguous outwardly camming engagement with thecorrespondingly curved top and bottom surfaces 11a of the base 10 at therear end of the base-provided nose 11. The advantage of the coactingcamming portions 11a, 13a will be explained hereinafter.

Referring now to Figures 3 and 5, it will be noted that the digging tip12 provides, as an integral part thereof and between wings-13, the twovertically spaced and parallel rearwardly extending lugs 15 whose rearends project beyond the rear ends of said wings 13 as best shown inFigure 3. These lugs 15 are wedge-form in cross-section and are ofsubstantial width as shown in Figure 3, they being located adjacent theinner surfaces of the respective wings 13 at points approximately midwaybetween the sides of the latter. It is particularly important to notethat the wedge-form of the lugs 15 is achieved by substantially planeside surfaces 15a which slant inwardly in the direction of the adjacentwing 13. It is also important to note that said lugs 15 embody whatmight be termed wing-carried base portions 16 (see Fig. which arecoextensive in width with the outer, or wing-adjacent, lug surfaces 150and terminate short of the wing and lug ends in nose portion-sustainedshoulders 16a (see Figs. 3 and 5) to which further reference will bemade later on herein.

In further carrying out the invention, 1 provide the digging tip 12 withthe integral boss 17 which is located at the curved inner end of thenose-receiving recess 14 approximately midway between the wing sides.This boss 17 is in bearing engagement, top and bottom, with the opposedsurfaces of lugs 15 adjacent the inner ends of the latter (see Figures 3and 5) so as to cooperate with the lug bases 16 in sustaining the wings13, and for another purpose which will be presently understood.

Coming now to the digging tip seating and sustaining formations of thenose portion 11 of the tooth base 10, and turning to Figures 4, 5 and 6,it will be observed that the top and bottom surfaces of the nose 11 eachprovide a rearwardly extending and groove-form lugreceiving seat 18.These seats 18 are open at their forward ends and are defined by theundercut side walls 19 which substantially conform to the slant of thelug sides 15a and flare laterally outward (1%) at the entry ends of thesockets to facilitate insertion of lugs 15. This outward wall flare 19aalso facilitates grinding of walls 19 and especially the inner endsthereof within the lug end receiving socket 18a to which reference willpresently be made.

The rear end of each lug-receiving seat 18 terminates in 9. lugend-receiving and sustaining socket 18a. The inner or bottom definingwall of each socket 18a curves outwardly as at 18b in the directon ofthe adjacent top or bottom surfaces of said base section (see Figure 5)to conform to the similar curve of the opposed and contacting endsurfaces b of the lugs. Thus the lug and socket surfaces 15b, 18b,cooperate with the aforementioned wing and nose surfaces 13a, 11a intending, cam fashion, to draw the wedging sides 15a of the lugs 15 intotight engagement with the undercut walls 19 of the related lug-receivingseats 18 of nose 11.

Also, as indicated, the rounded outer end of the nose 11 has thecut-out-provided seat 20 which snugly receives the boss 17 of tip recess14. This interengagement of boss 17 with nose seat 20 cooperates withthe lugs 15 and their seats 18, 18a to prevent relative lateral movementof the base 10 and tip 12 in service after the parts have beenassembled.

.In the illustrated embodiment of the invention, I employ the fiat sidedheavy duty wedge 23 as the means for securing the tip 12 and base 10 intight rigid assembly. The wedge 23 is projected through aligned andcorrespondingly shaped wing and nose holes 22, 21, respectively, asindicated in Figures 5 and 7. It is important to note that the wingholes 22 are located at the site of the respective lugs 15 and lug bases16 inwardly of the sides and rear shouldered end 16a of the latter. Thismeans that there is a maximum of digging tip-provided bearing surfaceand stock opposed to both of the broad and flat front and rear surfacesof wedge 23. The result is that the heavy duty wedge will absorb andcounteract any digging service-induced stresses tending to rock thedigging tip 12 vertically relatively of the base-provided nose 11, andthus tend to bend or break the socketed lug ends at the site of theshouldered outer ends of sockets 18a.

Referring again to the lugs 15 and to the groove-form nose-providedseats 18 therefor, one of the problems left unsolved by the prior art,but which is solved by my invention is to so form the interengagingstress-sustaining parts of a tooth base and digging tip as to readilyadmit of necessary grinding or machining of same to obtain a proper fitand avoid looseness. This I achieve by provision of the broad, unbrokenand preferably plane wedging sides 15a of the lugs 15; and also by thedrilled longitudinal bores 24 (see Figures 4 and 7) which open laterallyto the wedge-receiving seats 18 at the junctions of side walls 19, 19awith the bottom walls thereof. These bores 24 preferably extend the fulllength of the respective seats 18 and related lug end-receiving sockets18a, and as will be appreciated they enable a grinding tool to properlyact upon the full width of the groove bottoms and adjacent wedging walls19, 19a. Bores 24 also receive the side and bottom-defined edges of lugs15 to avoid binding in case the width of the seat bottom is less thanlug bottom width.

Figures 5 and 6 show that the nose 11 provides the transverselycoextensive shoulders 25 between the lug receiving sockets 18a and thecurved wing end-engaging surfaces 11a. When the wedge 23 is driven intoplace as in Figure 5 the lug base-provided shoulders 16a are drawnagainst these nose provided shoulders 25; and surfaces 11a, 13a as wellas surfaces 15b, 18b are jammed into engagement, as the nose 11 isjammed into the seating recess 14 of tip 12. As previously mentioned,the jamming together of surfaces 11a, 13a and 15b, 18b tends to produceforces in outward vertical directions as seen in Figure 5 whichaccentuate the wedging fit of lugs 15 in the seats 18, 18a.

The outward flaring (19a) of the side walls 19 at the entry ends of thelug seats 18 and the bevelled ends 15b of the lugs is also important inthat it facilitates assembly of the tip 12 and base 10 by admitting oflimited initial rocking of the former in planes normal to each other, asindicated by dotted lines and arrows in Fig. 6. The formations notedalso facilitate final separation of the tip and base as will beappreciated.

Having thus described my invention what I claim is:

1. A dipper tooth or the like providing a base section and a detachabledigging tip carried thereby, the base section having a forwardlyextending tip-seating nose providing top and bottom surfaces taperinginwardly to-- ward its forward end, the tip having rearwardly extendingtop and bottom wings providing a substantially longitudinallycoextensive open sided recess therebetween re ceiving and mounting thetip on said nose, a pair of vertically spaced and parallel wing-carriedlugs of wedgeform cross-section providing broad seat-bottom-engagingsurfaces, said lugs extending from adjacent the forward end of saidtip-provided recess and projecting beyond the rear ends of said wings,said lugs being located adacent different ones of said wings and each ofsaid lugs providing longitudinally coextensive and substantially planeuniformly spaced sides tapering transversely of said lugs in thedirection of the adacent wing, each of said lugs providing thickenedwing-carried portions substantially coextensive in width with thewing-adjacent outer surfaces thereof and terminating in shoulders shortof the rear ends of said wings, the top and bottom surfaces of said noseportion having rearwardly extending wedge-form seats having bottom wallsand undercut uniformly spaced side walls, said seats being open at theirforward ends and receiving the respective lugs, the rear end of eachseat terminating in a socket receiving the rear end of one of said lugs,each of s'aidsockets having 'a shoulder-providing wall portion overlyingthe outer surface of the received lug portion, the wall-providedshoulders of said sockets bearing against said lug base-providingshoulders when the tip and base are assembled, the fully engaged lugsand seats drawing said wings against adjacent nose surfaces whilepreventing relative lateral movement of said base and tip, a rearwardlyextending boss carried by said tip at the forward end only of saidnose-receiving recess and bearing top and bottom against opposedsurfaces of said lugs inwardly of the sides of the latter, the forwardend of said nose having a seating recess snugly receiving said tip bossto cooperate with the interengaged lugs and seats to prevent relativelateral movement of the base and tip, said nose and tip wings havingtransverse and alignable securing element-receiving holes, the wingholes extending through the thickened portions of said lugs, and aremovable fastener element extending through said aligned holes when thetip and base are assembled, said removable fastener element comprising aheavy duty wedge having broad and flat front and rear surfacescorresponding in width to and contiguously engaging the forward nosehole wall and the rear walls of said wing holes throughout the depth ofthe latter.

2. A dipper tooth or the like providing a base section and a detachabledigging tip carried thereby, the base section having a forwardlyextending tip-seating nose providing top and bottom surfaces taperinginwardly to ward its forward end, the tip having rearwardly extendingtop and bottom wings providing a substantially longitudinallycoextensive open sided recess therebetween receiving and mounting thetip on said nose, a pair of vertically spaced and parallel wing-carriedlugs of wedgeform cross-section providing broad seat-bottom-engagingsurfaces, said lugs extending from adjacent the forward end of saidtip-provided recess and projecting beyond the rear ends of said wings,said lugs being located adjacent different ones of said wings and eachof said lugs providing longitudinally coextensive and substantiallyplane uniformly spaced sides tapering transversely of said lugs in thedirection of the adjacent wing, each of said lugs providing thickenedwing-carried portions substantially coextensive in width with thewing-adjacent outer surfaces thereof, the top and bottom surfaces ofsaid nose portion having rearwardly extending wedgeform seats havingbottom and undercut uniformly spaced side walls, said seats being openat their forward ends and receiving the respective lugs, the fullengaged lugs and seats drawing said wings against adjacent nose surfaceswhile preventing relative lateral movement of said base and tip, arearwardly extending boss carried by said tip at the forward end only ofsaid nose-receiving recess and bearing top and bottom against opposedsurfaces of said lugs inwardly of the sides of the latter, the forwardend of said nose having a seating recess snugly receiving said tip bossto cooperate with the interengaged lugs and seats to prevent relativelateral movement of the base and tip, said nose and tip wings havingtransverse and alignable securing element-receiving holes, the wingholes extending through the thickened portions of said lugs, and aremovable fastener element extending through said aligned holes when thetip and base are assembled, said removable fastener element comprising aheavy duty wedge having broad and flat front and rear surfacescorresponding in gaging the forward nose hole wall and the rear walls ofsaid wing holes throughout the depth of the latter.

3. The combination set forth in claim 2, and the bottom wall surface ofeach lug seat at its inner end and the rear end of theseatbottom-engaging surface of each lug being inclined-outwardly toward theadjacent tip wing, and wherein the inner surfaces of'the wing ends andthe underlying contiguous nose surfaces are also outwardly inclined,whereby two forces are provided adjacent each of the top and bottom ofsaid nose tending to draw the lug 'sides in to tight engagement with thewalls of the nose-provided seat.

4. The combination set forth in claim 2 and wherein the nose-providedlug seat walls flare outwardly from a point substantially inwardly ofthe entry end of said seats whereby to admit of initial lateral rockingof the tip when the latter is being assembled on the tooth base and tofacilitate milling of the inner ends of the lug seat walls.

5. The combination set forth in claim 2 and wherein the nose-providedlug seat walls flare outwardly from a point substantially inwardly ofthe entry end of said seats and wherein the entire width of the rearends of the lugs are reduced in thickness, whereby to admit of initialrocking of the tip both up and down and laterally to facilitate assemblyof same on the nose.

6. The combination set forth in claim 2 and each of said nose-providedlug seats having at each side a laterally extending and longitudinallycoextensive recess into which the bottom wall and related side wallopen, whereby to admit the bottom and side wall-defined edges of saidlugs to assure of proper seat and lug side wall engagement in case theseat bottom wall is slightly less than lug bottom width.

7. A dipper tooth or the like comprising a base section and a detachableV-form digging tip providing top and bottom wings, the base sectionhaving a nose providing separate top and bottom forwardly opening seatsproviding a flat bottom wall and plane undercut side walls, said sidewalls flaring outwardly at and adjacent the seat entries and beinguniformly spaced inwardly thereof, the tip having a substantiallylongitudinally coextensive and open sided nose-receiving recess betweensaid wings, a pair of rearwardly extending and vertically spaced lugsprojecting beyond said tip recess and carried by the respective wings,said lugs providing uniformly spaced and plane undercut side surfacesand a flat bottom and being engageable in said respective nose seats,the outward side wall flare at the seat entries admitting of initiallateral play of the lugs when the tip and base are being assembled andalso facilitating milling of the seat walls, and each seat at leastinwardly of its laterally flared entry having at each side a laterallyextending and longitudinally coextensive recess into which the bottomwall and related side wall open, whereby to admit the adjacent bottomand side surface-defined edges of said lugs and avoid binding of same inthe seats in case the seat bottoms are underwidth as compared to thelugs.

8. A dipper tooth or the like comprising a base section and a detachableV-form digging tip providing top and bottom wings, the base sectionhaving a nose providing separate top and bottom forwardly opening seatsproviding a flat bottom wall and uniformly spaced and plane undercutside walls which flare outwardly at the seat entries and for asubstantial distance inwardly therefrom, the tip having a substantiallylongitudinally coextensive and open sided nose-receiving recess betweensaid wings, a pair of rearwardly extending and vertically spaced lugsprojecting beyond said tip recess and carried by the respective wings,said lugs providing uniformly spaced and plane undercut, side surfacesand a flat bottom and being engageable in said respective nose seats,the free ends of said lugs being of reduced thickness throughout theirentire width so as to admit of initial play of the width to andcontiguously enlugs in their seats in the depthwise direction of thelatter to facilitate assembly of the digging tip and base section, theoutward side wall-provided seat entry flare further admitting of laterallug play during such assembly, and each seat at least inwardly of itslaterally flared outer portion having at each side a laterally extendingand longitudinally coextensive recess into which the bottom wall andrelated side Wall open, whereby to admit the adjacent bottom and sidesurface-defined edges of said lugs and avoid binding of same in theseats in case the 0 seat bottoms are underwidth as compared to the lugs.

References Cited in the file of this patent UNITED STATES PATENTS1,016,181 Snyder Jan. 30, 1912 15 8 Pemberton June 27, 1916 Nichols Oct.9, 1917 Nichols et 31. Nov. 13, 1917 McMonegal July 12, 1921 Taylor June26, 1928 McKee Jan. 6, 1931 Mekeel Aug. 30, 1932 Graham Mar. 3, 1936Fellmeth Dec. 15, 1936 Bruton Feb. 4, 1941 Seal July 29, 1941 You'nieIan. 11, 1944 FOREIGN PATENTS Great Britain Jan. 11, 1917

